Cytogenetic damage in native Baltic Sea fish species: environmental risks associated with chemical munition dumping in the Gotland Basin of the Baltic Sea.

This study represents the first attempt to assess genotoxicity and cytotoxicity effects in herring (Clupea harengus membras), flounder (Platichthys flesus), and cod (Gadus morhua callarias) caught at 47 study stations, located close to chemical munition dumpsites in the Gotland Basin, the Baltic Sea. Herring sampled from stations located in the center of chemical munition dumpsites exhibited the highest levels of micronuclei (MN) and total genotoxicity (ΣGentox), which is defined as the sum of frequencies of such nuclear abnormalities as micronuclei, nuclear buds, nuclear buds on the filament, and bi-nucleated erythrocytes with nucleoplasmic bridges. Exceptionally high and high ΣGentox risks were determined for flounder (89.47%), herring (79.31%), and cod (50%) caught at the stations located close to the chemical munition dumpsites.

Induction of nuclear abnormalities in herring (Clupea harengus membras), flounder (Platichthys flesus), and Atlantic cod (Gadus morhua) collected from the southern part of the Gotland Basin-the Baltic Sea (2010-2017).

Eight nuclear abnormalities of genotoxicity and cytotoxicity were studied in peripheral blood erythrocytes of herring (Clupea harengus membras), flounder (Platichthys flesus), and Atlantic cod (Gadus morhua) sampled (2010-2017) from the Polish and the Lithuanian Exclusive Economic Zones (EEZ) in the Baltic Sea. At all study stations, total genotoxicity (∑Gentox) was found to be higher than total cytotoxicity (∑Cytox). A significant time-related decrease in genotoxicity was detected in the Lithuanian EEZ (2015-2017), while in the Polish EEZ (2014-2016), the opposite tendency was revealed. The highest ∑Gentox and ∑Cytox values recorded in fish sampled at the study stations located relatively close to each other clearly indicate an increased environmental genotoxicity and cytotoxicity pressure for fish in these areas. Exceptionally high and high-level genotoxicity risks to herring followed by those to flounder and cod were determined at a higher percentage of the stations studied.

Environmental genotoxicity and cytotoxicity levels in herring (Clupea harengus), flounder (Platichthys flesus) and cod (Gadus morhua) inhabiting the Gdansk Basin of the Baltic Sea.

Frequencies of eight nuclear abnormalities (NAs) reflecting environmental genotoxicity and cytotoxicity, were examined in 739 specimens of herring (Clupea harengus), flounder (Platichthys flesus) and cod (Gadus morhua) collected between 2009 and 2017 at 50 study stations located in the Gulf of Gdansk and the southern part of the Gdansk Deep (the Baltic Sea). The highest levels of geno-cytotoxicity were recorded in fish caught at stations located in close proximity to chemical and conventional munitions dumping sites or in zones polluted by Chemical Warfare Agents (CWAs). The values of NAs were significantly higher (up to 51-fold compared with the reference level) in herring caught at seven stations and in cod from one station located close to the munitions dumping sites. Exceptionally high total genotoxicity (∑Gtox) risk was found for flounder collected from 18 (72.0%) stations, herring caught at 12 (38.7%) stations and cod caught at four (17.4%) studied stations.

Marine litter on the seafloor of the southern Baltic.

Marine litter occurrence and composition were investigated during routine bottom trawl fish surveys type BITS performed in the Polish Maritime Areas (the southern Baltic Sea). Sampling covered a distance of 325km and an area of 16km2 at a depth range of 19-110m. Litter densities varying between 0 items/ha (34% of tows) and 2.23items/ha with a mean of 0.20items/ha (SD=0.30) are at the bottom range of densities reported from other shelf habitats worldwide at similar water depths. The majority of the items (40%) were found at a depth range of 51-60m. Overall, plastic was the most common litter type (67% of all items) found in all tows with litter. The results of this study indicate that despite the Baltic being a semi-enclosed basin, with a densely populated coastline and extensive shipping, marine litter pollution of the southern Baltic seafloor is low compared to other coastal areas.

Environmental genotoxicity assessment along the transport routes of chemical munitions leading to the dumping areas in the Baltic Sea.

The frequencies of micronuclei (MN), nuclear buds (NB) and nuclear buds on filament (NBf) were examined in 660 specimens of herring (Clupea harengus) collected in 2009-2014 at 65 study stations located mainly along the chemical munition transport routes in the Baltic Sea. The frequency of nuclear abnormalities was strongly increased in herring caught at four stations located close to chemical munition dumping sites, or CWAs - substances (chemical warfare agents) in sediments. Significant increase of MN, NB and NBf was observed in fish caught November 2010-2013 compared to 2009. The most significantly increased genotoxicity responses were recorded in fish caught at stations along CW (chemical weapons) transport routes, close to the Bornholm CW dumping area, in zones with CWAs in sediments and with oil-gas platforms.

Assessing the environmental genotoxicity risk in the Baltic Sea: frequencies of nuclear buds in blood erythrocytes of three native fish species.

Nuclear bud (NB) formation was investigated in blood erythrocytes of 1892 flounder Platichthys flesus, herring Clupea harengus, and eelpout Zoarces viviparus specimens that were collected at 82 sites representing different regions of the Baltic Sea in 2009-2011. This is the first attempt to evaluate the baseline levels of NB and rank the genotoxicity risk for native fish species. NB levels were compared to the previously published micronuclei (MN) data from the same individual fish specimens in order to compare the two methods of genotoxicity assessment and investigate the relationship between MN as the cytogenetic measure of genotoxicity and the DNA damage reflecting NB. In 2009-2011, elevated NB levels in 89.4% of flounder sampling groups indicated high and extremely high genotoxicity risk levels. Herring and eelpout sampling groups showed elevated levels of NB, 74.6 and 45.7%, respectively. In general, herring and eelpout NB measure was more sensitive as the genotoxicity biomarker than MN.

Density-dependence in space and time: opposite synchronous variations in population distribution and body condition in the Baltic Sea sprat (Sprattus sprattus) over three decades.

Spatio-temporal density-dependent processes are crucial regulatory factors for natural populations. However, there is a lack of studies addressing spatial density-dependence in fish growth. A previous investigation has suggested spatio-temporal density-dependence in body condition of Baltic sprat. Here, we used different techniques, such as centre of gravity, distance, and homogeneity indices, to better characterize the spatial and temporal variations in sprat density and body condition in the Baltic Proper. Our results evidenced a negative spatio-temporal co-variation between the centres of gravity of density and maximum condition. In the 1980s-early 1990s both centres were located in the middle of the Baltic Proper. From the mid 1990s the centres progressively separated in space, as the sprat population moved towards the north-eastern Baltic Proper, and the centre of maximum condition towards the south-western areas. Moreover, at low abundances, sprat density and condition were homogeneously distributed in space, whereas at high abundances both density and condition showed pronounced geographical gradients. The ecological processes potentially explaining the observed patterns were discussed in the light of the Ideal Free Distribution theory. We provide evidence that the shift in the spatial distribution of cod, the main predator of sprat, has been the main factor triggering the overall spatial changes in sprat density, and thus condition, during the past thirty years. The spatial indices shown here, synthesizing the spatio-temporal patterns of fish distribution, can support the implementation of the EU Marine Strategy Framework Directive.

Environmental genotoxicity and cytotoxicity in flounder (Platichthys flesus), herring (Clupea harengus) and Atlantic cod (Gadus morhua) from chemical munitions dumping zones in the southern Baltic Sea.

The data on environmental genotoxicity and cytotoxicity levels as well as on genotoxicity risk in flounder (Platichthys flesus), herring (Clupea harengus) and cod (Gadus morhua) collected in 2010-2012 at 42 stations located in chemical munitions dumping areas of the southern Baltic Sea are presented. The frequency of micronuclei, nuclear buds and nucleoplasmic bridges in erythrocytes was used as genotoxicity endpoint and the induction of fragmented-apoptotic, bi-nucleated and 8-shaped erythrocytes as cytotoxicity endpoint. The most significantly increased geno-cytotoxicity levels were determined in fish collected near known chemical munitions dumpsites. Extremely high genotoxicity risk for flounder were identified at 21 out of 24 stations, for herring at 29 out of 31 and for cod at 5 out of 10 stations studied. The reference level of genotoxicity was not recorded at any of the stations revealing that in the sampling area fish were affected generally.

Risk of environmental genotoxicity in the Baltic Sea over the period of 2009-2011 assessed by micronuclei frequencies in blood erythrocytes of flounder (Platichthys flesus), herring (Clupea harengus) and eelpout (Zoarces viviparus).

Environmental genotoxicity was investigated at 82 locations encompassing different regions of the Baltic Sea. Micronuclei (MN) analysis was performed in erythrocytes of 1892 specimens of flounder Platichthys flesus, herring Clupea harengus and eelpout Zoarces viviparus, three of the most common native fish species of the Baltic Sea collected in 2009-2011. MN background levels in fish were determined using data obtained in 2001-2011 from 107 Baltic sites. Extremely high genotoxicity risk zones were found for flounder at 11 stations out of 16 in 2009 and 33 stations of 41 in 2010-2011, for herring, at 5 of 18 stations in 2009 and 20 of 43 stations in 2010-2011, in eelpout only at one out of 29 stations. The sampling stations were restricted mainly to the southern and eastern Baltic Sea offshore zones and in most of them, MN frequencies in flounder and herring significantly exceeded the reference and background levels of micronuclei. This is a first attempt to evaluate the background MN responses, as well as low, high and extremely high genotoxicity risk levels for native fish species.